Filter for coffee makers



July 12, 1949. L. REICHOLD FILTER FOR COFFEE MAKERS Filed Oct. 5, 1946 INVENTOR. Z. up vv/a EE/c/mL 12.

Patented July 12, 1949 FILTER FOR COFFEE MAKERS Ludwig Reichold, Winsted, Conn., assignor to The Silex Company, Hartford, Conn, a corporation of Connecticut Application October 5, 1946, Serial No. 701,533

Claims.

This invention relates to a filter for coffee makers and more particularly to filters such as are used in vacuum-type coffee makers and which are constructed of glass or other similar brittle material.

The present invention is particularly adapted for such filters as shown and described in the U. S. Letters Patent to Louis V. Lucia, No.

2,370,674 dated March 6, 1945.

When such filters are constructed of glass, which is highly preferred, they have a tendency to chip when the attachment spring of the filter is suddenly released after having been stretched.

An object of this invention, therefore, is to provide means on said filter for absorbing shock from the spring so as to prevent chipping or breakage of the glass.

Further objects and advantages of this invention will be more clearly understood from the following description and from the accompanying drawing in which:

Fig. 1 is a plan view of said filter.

Fig. 2 is an elevational side view.

Fig. 3 is a fragmental side View, partly in section, illustrating the present invention.

As shown in the drawing, a filter embodying my invention may comprise a head 5 having a handle 6 and a depending stem 1 with a spiral groove 8 therein which receives coils 9 at the end of an anchoring spring l0, such as fully described in the above-mentioned patent.

It will be noted that in order to provide the spiral grooves 8, which form a thread in the stem I to receive the coils 9, there is required a spiral rib I! which must necessarily have an end portion such as at I2.

It has been found that when the spring I0 is suddenly released from a stretched position, the shock delivered by said spring against the end portion l2 has a tendency to chip the glass material of the'filter at that point, which tendency would be exceedingly objectionable in devices of this kind.

In order to eliminate the damage of breakage or chipping of the glass as above-described, I provide, at the end of the stem 1, a projecting portion or tip [3 which projects downwardly below the end portion l2 into the interior of the spring ID. The said portion is larger than the internal diameter of the spring so that in securing the spring to the stem l the said spring must be stretched, as clearly shown in Fig. 3, to provide a tight fit between the tip I 3 and the end portion of the spring. It will be noted that the bottom of the tip [3 is rounded so as to guide the spring 2 onto the said tip, particularly when it is released from a stretched position.

In the operation of the device, the filter head 5 is retained in position within the coffee maker by stretching the spring l0 and securing a hook at the bottom thereof to a convenient portion of the cofiee maker. Upon stretching the spring, the number of coils which fit over the tip I3, as shown in Fig. 3, will tend to slide downwardly for a short distance on said tip. Those coils sliding oif the tip will tend to close or return to their normal diameter. Upon sudden release of the spring, the end thrust created thereby will tend to force the said coils back onto the tip and the said tip, fitting tightly within the coils, will serve to absorb the shock from said thrust, by means of the friction which is provided between the end of the spring and the tip l3, and thereby prevent chipping or breaking of the material of said filter.

I claim:

1. A coffee maker filter of the character described having a head, a depending stem on said head, an anchoring spring secured to said stem, and a projection on the bottom of said stem cooperating with an end portion of said spring for frictionally resisting end thrust from said spring.

2. A coffee maker filtering device of the character described comprising a head portion, a spring secured to said portion, and a depending portion on said head in sliding and frictional engagement with the end portion of said spring for resisting end thrust from said spring.

3. A filter of the character described comprising a head having a depending stem with a spiral rib thereon providing a spiral groove, a spiral spring secured to said head by means of an end portion of said spring being threaded to said spiral roove, and an extension on said stem in frictional engagement with the said spring for absorbing shock upon said spring being released from a stretched condition.

4. A filter of the character described comprising a head having a stem depending therefrom, a spiral rib on said stem providing a spiral groove, a spiral spring secured to said stem by being threaded to said groove, and a downwardly projecting extension on said stem fitting within an end portion of the springs and having a diameter larger than the normal inside diameter of the spring for providing frictional engagement between the end portion thereof and said extension to absorb shock caused by end thrust from said spring upon the release thereof from a stretched condition.

10 Number and a rounded end portion on said projection for guiding the said spring thereon.

LUDWIG REICHOLD;

REFERENCES CITED The following referenlces are of record in the file of this patent:

UNITED STATES PATENTS Name Date 2,370,674 Lucia Mar. 6, 1945 

